Image Analysis of Indications in Fillet Welding by Phased Array Ultrasonic Technique

2017 ◽  
Author(s):  
Youwei Zhang ◽  
Yuqing Yang ◽  
Qingfeng Li ◽  
Le Chen
Keyword(s):  
Ultrasonic Testing ◽  
Phased Array ◽  
Surface Defects ◽  
Great Influence ◽  
Focal Depth ◽  
Slag Inclusion ◽  
Butt Weld ◽  
Near Surface ◽  
Butt Welding ◽  
Fillet Welding

The steel frame for carrying boiler in power generation station is usually connected by fillet welding like corner or tee joints. Traditionally, we inspect this type of welding by Magnetic Particle Testing (MT) and Dye Penetration Testing (PT), by which only the surface or near surface defects can be detected, and the internal defects in butt welding is inspected by Ultrasonic Testing (UT) and Radiographic Testing (RT). Though ultrasonic Testing (UT) has various advantage in flat butt weld, it requires a better condition on the detection surface avoiding the interference of being rough, irregular in shape, very small or thin, or not homogeneous. Due to the geometric shape or structural constrains in fillet welding, volumetric defects are sometimes unable to be detected by RT. Currently, there are no effective methods of Non-destructive examination (NDE) for the volumetric flaws in this type of welding which connects the steel column and reinforcing plate. Normally, the volumetric and plannar defects of fillet welding are commonly as: incomplete penetration, slag inclusion, porosity, lack of fusion and cracks, which have a great influence on the welding quality. This paper aims at using the advantages of Phased Array Ultrasonic Testing (PAUT) to detect the fillet weld: • Focal depth is variable. • Scanning range is large, steering beam from −89° to 89°. • Covering large volume at single position of probe. By setting different types of artificial flaws, we carried out the reliability analysis of this kind of welding with PAUT. Through observing the representative images of flaws, we can directly know the location of defects in the weld. According to the data provided by the scan software, we can read its depth and distance from the weld center line, which helps us to locate defects in weld precisely.

scholarly journals Caracterización dimensional con ultrasonido por arreglo de fases de discontinuidades inducidas en acero ASTM A36 mediante procesos de electroerosión y soldadura SMAW

2021 ◽  
Vol 20 (3) ◽  
Author(s):  
Carlos Andrés Galán-Pinilla ◽  
Luz Amparo Quintero-Ortiz ◽  
Julián Orlando Herrera-Ortiz
Keyword(s):  
Ultrasonic Testing ◽  
Phased Array ◽  
Ultrasonic Beam ◽  
Butt Weld ◽  
Second Stage ◽  
A36 Steel ◽  
Ultrasound Inspection ◽  
Two Stages ◽  
Geometric Morphology ◽  
Phase Arrangement

This research evaluates the effect of the variables of Phased Array Ultrasonic Testing(PAUT) on the sectoral angular beam scans “S-Scan” and the geometric morphology of planar discontinuities such as the inclination forthe ultrasonic beam and the shape of the extremity on accuracy in measurements. The study was carried out in two stages. Duringthe first stage, eight ASTM A36 steel samples with machined notches by penetration from EDM and a welded sample with lack of penetration in a butt weld were designed and produced. In the second stage, it wasmeasured the size of the discontinuities using ultrasound inspection and different configurations of the phase arrangement. The effect of each variable and inspection setting with errors between 0.2 % and 120 % were determined by statistical analysis.

Productivity and Reliability Study of Non Destructive Testing Techniques for Inspection of Structural Welds in Construction Industry

NDT World ◽  
2016 ◽  
Vol 19 (3) ◽  
pp. 35-39
Author(s):  
Чан ◽  
Alan Chan ◽  
Бабу ◽  
Sajeesh Kumar Babu ◽  
Чан ◽  
...  
Keyword(s):  
Construction Industry ◽  
Ultrasonic Testing ◽  
Phased Array ◽  
Flaw Detection ◽  
Slag Inclusion ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Ultrasonic Techniques ◽  
Testing Techniques ◽  
Non Destructive

Introduction. The aim of this study is to evaluate the productivity and reliability of non-destructive testing techniques for the inspection of structural welds employed in the Hong Kong construction industry. Method. Manual ultrasonic pulse echo method and semi-automatic ultrasonic techniques using phased array (PAUT) as well as radiographic testing were employed. Five classes of defects were analyzed: lack of penetration, lack of fusion, crack, porosity and slag inclusion. The tests were carried out on the specimen made from structural plate, on which artefacts were inserted on the weld metal. The results were being studied to compare the defect detection reliability by both ultrasonic techniques. The flaw detection productivity using phased array is also compared with conventional ultrasonic testing at a determined rate. Results. The reliability of PAUT was 100% compared to 96.7% with manual ultrasonic testing, however with the inclusion of defect sizing and tolerance the reliability of manual UT is dropped to 57.4%, which implies there is a chance of 42.6% of improper sizing). PAUT exhibits the reliability of 87.5%. The research will be continued with the aim of determining the most appropriate and reliable NDT methods in each case.

scholarly journals Wavenumber Imaging of Near-Surface Defects in Rails using Green’s Function Reconstruction of Ultrasonic Diffuse Fields

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3744 ◽  
Author(s):  
Hui Zhang ◽  
Haiyan Zhang ◽  
Jiayan Zhang ◽  
Jianquan Liu ◽  
Wenfa Zhu ◽  
...  
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Phased Array ◽  
Surface Defects ◽  
Measured Signal ◽  
Near Surface ◽  
Diffuse Fields ◽  
Ultrasonic Phased Array ◽  
The Cross ◽  
Function Reconstruction

Wavenumber imaging with Green’s function reconstruction of ultrasonic diffuse fields is used to realize fast imaging of near-surface defects in rails. Ultrasonic phased array has been widely used in industries because of its high sensitivity and strong flexibility. However, the directly measured signal is always complicated by noise caused by physical limitations of the acquisition system. To overcome this problem, the cross-correlations of the diffuse field signals captured by the probe are performed to reconstruct the Green’s function. These reconstructed signals can restore the early time information from the noise. Experiments were conducted on rails with near-surface defects. The results confirm the effectiveness of the cross-correlation method to reconstruct the Green’s function for the detection of near-surface defects. Different kinds of ultrasonic phased array probes were applied to collect experimental data on the surface of the rails. The Green’s function recovery is related to the number of phased array elements and the excitation frequency. In addition, the duration and starting time of the time-windowed diffuse signals were explored in order to achieve high-quality defect images.

scholarly journals Quality Control Approach for the Detection of Internal Lower Density Areas in Composite Disks in Industrial Conditions Based on a Combination of NDT Techniques

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7174
Author(s):  
Andrzej Katunin ◽  
Krzysztof Dragan ◽  
Tomasz Nowak ◽  
Marek Chalimoniuk
Keyword(s):  
Quality Control ◽  
Infrared Thermography ◽  
Ultrasonic Testing ◽  
Surface Defects ◽  
Polymer Matrix Composites ◽  
Hybrid Approach ◽  
Testing Procedure ◽  
Near Surface ◽  
Manufacturing Defects ◽  
Control Approach

Voids in polymer matrix composites are one of the most common manufacturing defects, which may influence the mechanical properties and structural behavior of the final parts made of composites by various manufacturing methods. Therefore, numerous non-destructive testing (NDT) techniques were developed and applied for quality control and in-service testing of such structures. In this paper, the authors analyzed various alternatives to the reference technique, X-ray computed tomography (XCT) NDT, which is used for industrial testing of composite disks having defects in the form of the lower density areas. Different candidates, namely: vibration-based testing, infrared thermography, vibro-thermography, as well as ultrasonic testing were analyzed in terms of their sensitivity and technical feasibility. The quality of the results, the complexity of the testing procedure, time and labor consumption, and the cost of the equipment were analyzed and compared with the reference technique. Based on the conducted research the authors finally proposed a hybrid approach to quality control, using a combination of two NDT techniques–infrared thermography (for initial scanning and detection of near-surface defects) and ultrasonic testing (for a more detailed analysis of products that pass the first testing procedure). It allowed for replacing the costly XCT diagnostics with a much cheaper, but almost equally effective, alternative.

scholarly journals Autoencoder-based detection of near-surface defects in ultrasonic testing

Ultrasonics ◽  
2021 ◽  
pp. 106637
Author(s):  
Jong Moon Ha ◽  
Hong Min Seung ◽  
Wonjae Choi
Keyword(s):  
Ultrasonic Testing ◽  
Surface Defects ◽  
Near Surface

scholarly journals Phase Coherence Imaging for Near-Surface Defects in Rails Using Cross-Correlation of Ultrasonic Diffuse Fields

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 868
Author(s):  
Haiyan Zhang ◽  
Mintao Shao ◽  
Guopeng Fan ◽  
Hui Zhang ◽  
Wenfa Zhu ◽  
...  
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Cross Correlation ◽  
Phased Array ◽  
Surface Defects ◽  
Performance Indicator ◽  
Phase Coherence ◽  
Near Surface ◽  
Diffuse Fields ◽  
Coherence Imaging

In this paper, phase coherence imaging is proposed to improve spatial resolution and signal-to-noise ratio (SNR) of near-surface defects in rails using cross-correlation of ultrasonic diffuse fields. The direct signals acquired by the phased array are often obscured by nonlinear effects. Thus, the output image processed by conventional post-processing algorithms, like total focus method (TFM), has a blind zone close to the array. To overcome this problem, the diffuse fields, which contain spatial phase correlations, are applied to recover Green’s function. In addition, with the purpose of improving image quality, the Green’s function is further weighted by a special coherent factor, sign coherence factor (SCF), for grating and side lobes suppression. Experiments are conducted on two rails and data acquisition is completed by a commercial 32-element phased array. The quantitative performance comparison of TFM and SCF images is implemented in terms of the array performance indicator (API) and SNR. The results show that the API of SCF is significantly lower than that of TFM. As for SNR, SCF achieved a better SNR than that of TFM. The study in this paper provides an experimental reference for detecting near-surface defects in the rails.

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